Easily openable carton with elongated adherence areas near the side edges of the overlapped flap

ABSTRACT

A carton end closure formed of two flaps adhesively held together at a number of distinct areas. One of these areas is elongated with its longitudinal axis pointed toward one corner of the overlapped flap. Another of these areas is also elongated with its longitudinal axis pointed toward another corner of the overlapped flap. Another of these areas is located in the center portion of the overlapped flap. At each of these distinct areas of adherence one of the overlapped flaps is embossed.

United States Patent 1 March 6, 1973 Brastad EASILY OPENABLE CARTON WITH ELONGATED ADHERENCE AREAS NEAR THE SIDE EDGES OF THE OVERLAPPED FLAP [75] Inventor: William A. Brastad, Minneapolis,

Minn.

[73] Assignee: General Mills, Inc.

[22] Filed: May 4, 1970 [21] Appl. No.: 34,194

[52] US. Cl ..229/5l WB [51] Int. Cl. ..B65d 5/54 [58] Field of Search ..229/51 TC, 51 SC, 51 WB [56] References Cited UNITED STATES PATENTS 2,281,304 4/1942 Gillian ..229/51 WB X 2,828,060 3/1958 Brown ..229/51 SC X 3,543,997 Michetti..... ..229/5l TC 3,195,796 7/1965 Buttery ..229/5l \VB 2,789,746 4/1957 Hovland ..229/51 TC 2,317,773 4/1943 Kavanaugh.... ...229/5l WB 3,491,937 1/1970 Brastad ..229/51 TC Primary ExaminerLeonard Summer Attorney-Anthony A. Juettner and Kenneth D. Ohm

[57] ABSTRACT 2 Claims, 7 Drawing Figures EASILY OPENABLE CARTON WITH ELONGATED ADHERENCE AREAS NEAR THE SIDE EDGES OF THE OVERLAPPED FLAP The present invention relates to improvements in carton closures. More particularly, it pertains to an improved closure formed of two flaps having an arrangement of adhered embossed areas which permit easy separation of such flaps while at the same time holding the side edges of such flaps together.

Cartons formed of paperboard such as bleached kraft, white coated paper newsboard, chipboard, and similar materials are well known to the art and are widely used. Cartons made of these materials having end closures which are adhesively held together to protect their contents and to avoid premature accidental opening are sometimes difficult to open without the aid of a knife or other opening instrument. One common structure which is used to open such cartons is a closure formed of two overlapping flaps releasably adhesively held together, with the outermost of said flaps having an opening tab portion attached thereto and projecting therefrom which when pulled upwardly and away from the closure causes said flaps to separate. When said flaps separate, they are folded back and access to the carton contents is gained. It has been found when using this common structure that at times the flaps are so securely held together by the adhesive, that pulling the opening tab member upwardly and away from the closure causes the uppermost flap to tear rather than separate neatly from the other flap.

Accordingly, it is one object of the present invention to provide an opening structure which for a given amount of adhesive applied between two end closure flaps increases the possibility of releasable adhesion between such flaps and holding the side edges of such flaps together while at the same time reducing the pos' sibility of the uppermost such flap tearing when pulled upwardly and away from'the innermost flap.

Other objects and advantages of the present invention will be apparent from the following description in which certain preferred embodiments of the invention are disclosed.

In the drawings which form a part of this application,

FIG. 1 is a plane view of a carton blank for forming one embodiment of the present invention;

FIG. 2 is a perspective view of a carton end closure formed from the carton blank of FIG. 1 with some of the closure flaps being folded to close the carton end;

FIG. 3 is a perspective view similar to FIG. 2 with another of the closure flaps being folded to close the carton end;

FIG. 4 is a perspective view of the carton of FIGS. 2 and 3 with all of the closure flaps folded to close the carton end;

FIG. 5 is a perspective view of the carton of FIGS. 2-4 illustrating the manner in which the carton is opened by pulling the opening pull tab portion of the outermost closure flap upwardly and away from the end closure;

FIG. 6 is a perspective view of the carton of FIGS. 2-5 with the outermost flap having been pulled away from the end closure shown in FIG. 4; and

FIG. 7 is a perspective view of the carton embodying the present invention which has been reclosed by tucking the pull tab of the opening tab portion of the outermost flap into a slit formed in the other flap of the end closure.

In FIG. 1 a blank 10 is illustrated for forming the carton end closure of the present invention. The blank 10 for forming the carton 12 (illustrated in FIG. 2) is formed out of paperboard material such as bleached kraft, white coated paper newsboard, chipboard or other materials well known to the carton art.

The blank 10 is shown with the surface which later becomes the outside of the carton 12 being uppennost. The blank 10 comprises a glue panel 14, a front side panel 16, a first end side panel 18, a rear side panel 20, and a second end side panel 22. The side panels are hingedly connected at score lines 24, 26, 28 and 30, as shown in FIG. I. Hingedly attached to the lower portions of the side panels l6, 18, 20 and 22, are bottom end flaps 32, 34, 36 and 38 respectively. Said bottom flap attachment is along a score line 40. Hingedly attached to the upper portions of the side panels 16, 18, 20 and 22 are top end closureflaps 42, 44, 46 and 48, respectively. The top end flap 42 has side edges 42a and 42b. The flaps 44 and 48 are sometimes hereinafter referred to as tabs. Said top flap attachment is along a score line 50.

The top end flap 46 has a tab 52 extending therefrom and has side edges 46a and 46b. The top end flap 42 has a free edge 53 and an inverted C-type slit 54 therein. The tab 52 and the slit 54 are designed and positioned so that when the carton 12 (see FIG. 2) has been opened once and it is desired to reclose said carton, the tab 52 can be inserted into. the slit 54 as shown in FIG. 7.

The closure flap 46 has a closure flap portion 46c and an opening portion 46d which includes the pull tab 52. The portions 46c and 46d are contiguous along a predetermined line 56. The line 56 has means associated therewith to facilitate the upward bending of the opening portion 46d including the tab 52 relative to the closure flap portion 460 along said line when a force is exerted on said tab upwardly and away from the end closure of the carton as is illustrated by arrow A in FIG. 5. In the preferred embodiment this means is a perforated line coincident with the line 56. The perforated line extends completely across the base of the opening portion from the side edge 46a of the closure flap 46 to the side edge 46b of the closure flap 46.

To secure the carton body in its tubular shape as is illustrated in FIG. 2, the glue panel 14 is adhesively bonded to the inner surface of the second side end panel 22, i.e., the surface of said panel 22 which cannot be seen in FIG. 1.

The closure flaps or tabs 44 and 48 which are hingedly attached to the end side panels 18 and 22, respectively, are provided with a glue resistant material, such as varnish, at selected areas 58 and 60, respectively, on the upper surfaces. In the area 58 a circular area or spot 62 is left free from adhesive resistant material and thus only the adhesive which penetrates spot 62 will tend to hold the flap 42 against the flap 44 when flap 42 is placed to overlie said flap 44. This spot 62 may be supplemented by auxiliary varnish free areas which also will be susceptible to glue and will strengthen the union between the flap 42 and the flap 44. Similarly, the area has a circular area or spot 64 which is left free from adhesive resistant material and thus only the adhesive which penetrates the spot 64 will tend to hold the flap 42 against the flap 48 when flap 42 is placed to overlie said flap 48. The area 64 may also be supplemented by auxiliary varnish free areas which will be susceptible to glue and will strengthen the union between the flaps 42 and 48. Limiting the areas of adhesive attachment between flap 42 and flaps 44 and 48 as set forth provides a limited readily releasable adhesive bond between flap 42 and flaps 44 and 48 when an aqueous adhesive is applied to the spots 62 and 64. This limited readily releasable bond permits ready separation of said flaps when a force is exerted thereon, while at the same time bonding said flaps together against premature accidental separation.

As shown in FIG. 1, the top surface of flap 42 is provided with a glue resistant material, such as varnish, in the area 66. In this area 66 are located a number of distinct areas 68. The areas 68 are embossed in the upper surface of the flap 42, i.e., the areas 68 are raised above the upper surface of the flap 42, and are left free from adhesive resistant material and thus the adhesive which penetrates the distinct areas 68 will tend to hold the center portion of the closure flap 46 against the center portion of the flap 42. The distinct areas 68 may be supplemented by auxiliary varnish free embossed areas which will also be susceptible to glue and will strengthen the union between the closure flap 46 and the flap 42.

Extending from the free edge 53 of the flap 42 along the periphery of each of the distinct areas 68 to the free edge 53 of the flap 42 are partial cuts 70. These cuts 70 extend partially through the closure flap 42 from the upper surface thereof toward the bottom surface thereof, i.e., from the surface seen in FIG. 1 toward the surface of the flap 42 which cannot be seen in FIG. 1. As shown in FIG. 1, the portions of the cut 70 which extend along either side of one particular distinct area 68 are angled to converge toward each other as they extend farther away from the free edge 53. The cuts 70 can extend from 25 to 50 percent through the closure flap 42, with the preferred range being from 30 to 40 percent through the closure flap 42. In any event the cuts 70 should extend through the flap 42 at least as far as the adhesive used to bond the flaps 42 and 46 penetrates flap 42.

As shown in FIG. 1, the top surface of the flap 42 is provided with elongated embossed areas 72 and 74 which are left free from adhesive resistant material and thus the adhesive which penetrates the areas 72 and 74 will tend to hold the ends of the closure flaps 42 and 46 together. The area 72 is located near one free corner of the flap 42, i.e., at the corner of the flap 42 where the side edge 42a and free edge 53 meet. The longitudinal axis 76 of elongated area 72, if extended, forms an angle a with the free edge 53. The axis 76 is pointed toward the free corner of the flap 42 where the side edge 42a and free edge 53 meet. The area 74 is located near another free corner of the flap 42, i.e., at the corner of the flap 42 where the side edge 42b and free edge 53 meet. The longitudinal axis 78 of the elongated area 74, if extended, forms an angle b with the free edge 53. The axis 78 is pointed toward the free comer of the flap 42 where the side edge 42b and the free edge 53 meet. The angles a and b are approximately 60 with the preferred range being from 45 to 75.

Extending along the periphery of each on the elongated embossed areas 72 and 74 are partial cuts 80 and 82, respectively. These cuts 80 and 82 extend partially through the closure flap 42 from the upper surface thereof toward the bottom surface thereof, i.e., from the surface seen in FIG. 1 toward the surface of the flap 42 which cannot be seen in FIG. 1. The cuts and 82 can extend from 25 to 50 percent through the closure flap 42, with the preferred range being from 30 to 40 percent through the closure flap 42. In any event the cuts 80 and 82 should extend through the flap 42 at least as far as the adhesive used to bond the flaps 42 and 46 penetrates flap 42.

Embossing the areas 68, 72 and 74, i.e., raising the areas 68, 72 and 74 above the upper surface of the flap 42, facilitates providing adhesion between the flaps 42 and 46 in only desired areas when adhesive is provided between said flaps. Also, if the adhesive resistant characteristics of the adhesive resistant material applied to define the adhesive areas 68, 72 and 74 are inadequate, the embossing of such areas will tend to separate the flaps 42 and 46 where no adhesion is intended and prevent unwanted adhesion. This type of bond together with the partial cuts 70, 80 and 82, permits ready separation of the flaps 42 and 46 when a force is exerted to the pull tab 52 upwardly and away from the end closure as shown by arrow A in FIG. 5, while at the same time facilitating holding the adjacent side edges, 42a 46a and 42b-46b, of said flaps together.

To close the carton end, the end closure flaps 44 and 48 are folded across the end of the carton as illustrated in FIG. 2, and an adhesive is applied to the distinct areas or spots 62 and 64 of the uppermost surfaces of end flaps or tabs 44 and 48. The first closure flap 42 is then closed as in FIG. 3 and an adhesive is applied to the areas 68, 72 and 74. The adhesive applied can be either an aqueous adhesive or a hot melt adhesive just as long as the bond between the flaps 42 and 46 caused thereby is limited to the areas 68, 72 and 74. The area 68 can take shapes other than as shown, for example, a triangle, while the areas 72 and 74 can take shapes other than as shown, for example, diamonds or rectangles. In addition, the embossed areas 68, 72 and 74 could be in the flap 46 rather than the flap 42.

It will be noted that the width across the narrow dimension of the first closure flap 42 is less than the width of the carton end so that said flap does not cover the entire carton end when said flap is folded as shown in FIG. 3. The second closure flap 46 is then folded down about hinge line 50 to partially overlie the first closure flap 42 to complete the sealed carton which appears in its closed form in FIG. 4 with a portion of side edge 46a overlying a portion of side edge 42a and with a portion of side edge 46b overlying a portion of side edge 42b. As shown in FIG. 4, the second closure flap 46 extends less than the width of the carton across the end closure and the pull tab 52 which is connected to closure flap 46 extends farther across said end closure.

As shown in FIG. 5, the carton 12 is easily opened by grasping the tab 52 and bending said tab upwardly and away from the first flap 42. This causes the tab 52 to fold about hinge line 56, into the position shown in FIG. 5. Now, when additional force is applied to the tab 52 in the direction of the arrow A, the flaps 42 and 46 can be separated and flap 46 can be moved to the position shown in FIG. 2. In the preferred embodiment, when the additional force is applied to the tab 52in the direction of the arrow A, the adhesive bond in the areas 68, 72 and 74 between closure flap 46 and flap 42 causes the flap 42 to begin to delaminate. In the areas 68 this delamination begins at the narrower or smaller end of the areas 68 and is controlled to remain within the areas 68 by the partial cuts 70 and the free edge 53 of the flap 42. The partial cuts 70 facilitate and control this delamination of the flap 42 so that it extends from the narrower or smaller end of each area 68 to the wider or larger end of each such area, i.e., to the free edge 53 of the flap 42 adjacent each such area. The delaminated parts of the flap 42 from the areas 68 are shown by the numerals 84 in FIG. 6.

In the areas 72 and 74, the delamination begins near the ends of the areas 72 and 74 closest to the hinge line of the flap 42 and is controlled to remain within the areas 72 and 74 by the partial cuts 80 and 82, respectively. The partial cuts 80 and 82 facilitate and control this delamination of the flap 42 in the areas 72 and 74 so it begins in portions of such areas near the hinge line of the flap 42 and extends toward the free edge 53 of the flap 42. The delaminated parts of the flap 42 from the areas 72 and 74 are shown by the numerals 86 and 88, respectively.

By grasping flap 42 and exerting an upward force thereon the adhesive bond between flap 42 and flaps 44 and 48 in the distinct areas 62 and 64 is broken and said flap 42 can be moved to the position shownin FIG. 2. The varnish free areas, 62 on flap 44, and 64 on flap 48, are sufficiently small so that the glue in said areas readily releases the flaps joined together thereby when a force is exerted to separate said flaps. The bond created in these areas 62, 64, 68, 72, and 74 is thus a limited bond for ready separation of the flaps joined thereby when a force is exerted on said flaps while at the same time bonding said flaps together.

Reclosure of the open package shown in FIG. 2 without the use of adhesive bond is effected by moving the flap 42 back to the position shown in FIG. 3, then moving the flap 46 into the position shown in FIG. 7 and tucking the tab 52 into the slit 54.

In view of the principles set forth herein I have shown some of the ways of carrying out the present invention and some of the equivalents which are suggested by these disclosures.

Now, therefore, I claim:

1. A carton end closure for a carton body comprising a first flap hingedly attached along a first line to the carton body, a second flap hingedly attached along a second line to the carton body, said second flap at least partially overlying said first flap, said first flap having two side edges and having a free edge underlying said second flap, said second flap having two side edges, at least one of said flaps having an embossed area on the surface thereof in substantially the center portion, said center portion embossed area including at least three distinct embossed areas which extend to said free edge and are wider at said free edge than at the portion thereof farthest away from said free edge, said distinct embossed areas in substantially the center portion have partial cuts extending along at least a portion of the periphery of each of said distinct embossed areas, at least one of said flaps having an elongated embossed area on the surface thereof near one side edge of one of said flaps positioned with its longitudinal axis pointed toward one of the free corners of said first flap, at least one of said flaps having an elongated embossed area on the surface thereof near the other side edge of said one of said flaps positioned with its longitudinal axis pointed toward the other free corner of said first flap, said elongated embossed areas each have a partial cut extending along substantially the entire peripheries thereof, and means providing an adhesive bond between said first and second overlapping flaps in said embossed areas.

2. A carton end closure for a carton body comprising a first flap hingedly attached along a first line to the carton body, a second flap hingedly attached along a second line to the carton body, said second flap at least partially overlying said first flap, said first flap having two side edges and having a free edge underlying said second flap, said second flap having two side edges, at least one of said flaps having an embossed area on the surface thereof in substantially the center portion, said center portion embossed area including at least three distinct embossed areas which extend to said free edge and are wider at said free edge than at the portion thereof farthest away from said free edge, said distinct embossed areas in substantially the center portion have partial cuts extending along at least a portion of the periphery of each of said distinct embossed areas, at least one of said flaps having an elongated embossed area on the surface thereof near one side edge of one of said flaps positioned with its longitudinal axis at an angle of from 45 to from said free edge, at least one of said flaps having an elongated embossed area on the surface thereof near the other side edge of said one of said flaps positioned with its longitudinal axis at an angle of from 45 to 75 from said free edge, said elongated embossed areas each have a partial cut extending along substantially the entire peripheries thereof, and means providing an adhesive bond between said first and second overlapping flaps in said embossed areas. 

1. A carton end closure for a carton body comprising a first flap hingedly attached along a first line to the carton body, a second flap hingedly attached along a second line to the carton body, said second flap at least partially overlying said first flap, said first flap having two side edges and having a free edge underlying said second flap, said second flap having two side edges, at least one of said flaps having an embossed area on the surface thereof in substantially the center portion, said center portion embossed area including at least three distinct embossed areas which extend to said free edge and are wider at said free edge than at the portion thereof farthest away from said free edge, said distinct embossed areas in substantially the center portion have partial cuts extending along at least a portion of the periphery of each of said distinct embossed areas, at least one of said flaps having an elongated embossed area on the surface thereof near one side edge of one of said flaps positioned with its longitudinal axis pointed toward one of the free corners of said first flap, at least one of said flaps having an elongated embossed area on the surface thereof near the other side edge of said one of said flaps positioned with its longitudinal axis pointed toward the other free corner of said first flap, said elongated embossed areas each have a partial cut extending along substantially the entire peripheries thereof, and means providing an adhesive bond between said first and second overlapping flaps in said embossed areas.
 1. A carton end closure for a carton body comprising a first flap hingedly attached along a first line to the carton body, a second flap hingedly attached along a second line to the carton body, said second flap at least partially overlying said first flap, said first flap having two side edges and having a free edge underlying said second flap, said second flap having two side edges, at least one of said flaps having an embossed area on the surface thereof in substantially the center portion, said center portion embossed area including at least three distinct embossed areas which extend to said free edge and are wider at said free edge than at the portion thereof farthest away from said free edge, said distinct embossed areas in substantially the center portion have partial cuts extending along at least a portion of the periphery of each of said distinct embossed areas, at least one of said flaps having an elongated embossed area on the surface thereof near one side edge of one of said flaps positioned with its longitudinal axis pointed toward one of the free corners of said first flap, at least one of said flaps having an elongated embossed area on the surface thereof near the other side edge of said one of said flaps positioned with its longitudinal axis pointed toward the other free corner of said first flap, said elongated embossed areas each have a partial cut extending along substantially the entire peripheries thereof, and means providing an adhesive bond between said first and second overlapping flaps in said embossed areas. 